Complex data sets raise challenging ethical questions about risk to individuals who are not sufficiently covered by computer science training, ethics codes, or Institutional Review Boards (IRBs). The use of publicly available, corporate, and government data sets may reveal human practices, behaviors, and interactions in unintended ways, creating the need for new kinds of ethical support. Secondary data use invokes privacy and consent concerns. A team at Data & Society recently conducted interviews and campus visits with computer science researchers and librarians at eight U.S. universities to examine the role of research librarians in assisting technical researchers as they navigate emerging issues of privacy, ethics, and equitable access to data at different phases of the research process.1